1. Field of the Invention
The present invention generally relates to wiring, and more particularly to a method for connecting a routing device in existing wiring.
2. The Prior Arts
The rapid advancement of Internet technology has spurred various exciting applications. Among them, VoIP (voice over IP) is probably the most popular and promising one. In the early days of VoIP, hobbyist talked to each other over public Internet using their computers and suffered a great deal from the often-terrible voice quality. As the communications bandwidth is continuously expanded, more effective encoding/decoding schemes are adopted, and interoperability issues are resolved, VoIP has become more and more a serious communications mechanism in recent years to most people, in the office and household alike.
On the other hand, conventional analog telephones and public switched telephone network (PSTN) have been with us for more than 100 years. Due to its reliability and ubiquity, voice communications conducted over fixed telephone lines still constitute a very large portion of the world's voice traffic. It is widely believed that PSTN and VoIP would coexist peacefully with each other for many years to come.
Then, the problem becomes how to seamlessly integrate PSTN and VoIP, so that people would enjoy the benefit from the two totally different technologies Traditionally, voice networks (such as PSTN) and data networks (such as Internet) are built on two totally separate infrastructures. Even though carriers around the world are investing astronomical amount of money to build the so-called Next Generation Network (NGN), hoping to have a single backbone for carrying both voice and data traffics, for customer premises such as households and offices, there aren't many successful integrations of voice networks and data networks.
For most, if not all, households, there is an existing wiring for connecting a number of analog telephone sets to one or two telephone lines, which in turn connects to the PSTN. On the data side, some of these households have a dedicated link to public Internet via mechanisms such as ADSL and cable modem, and there is a local area network (wired or wireless) for connecting a number of computing devices in the household and sharing the bandwidth to the Internet. Various approaches have been proposed to integrate the existing telephone line wiring and the local area network so that existing telephone sets could be used to make VoIP calls as well.
One such approach is to use a device called IP PBX as shown in FIG. 1(a). As shown in FIG. 1(a), the IP PBX 100 is connected to the PSTN 10 via a telephone line 110 and connected to the telephone sets 60 via a wiring 20. The IP PBX 100 also connects to the local area network 50 so that the IP PBX 100 shares the dedicated link 130 to the public Internet 30 with computing devices 70. When a user (not shown) would like to make a call, the user picks up one of the telephone sets 60 and could select to make a PSTN call or a VoIP call by typing on the telephone set 60's keypad a special prefix. Based on the prefix, the IP PBX 100 then decides where to route the call. IP PBX is not yet very popular due to its high cost and is usually installed in office environments as there is a large of number of telephone sets and a large amount of voice traffic so as to justify the IP PBX's high cost. As most offices already have conventional PBX (which could make PSTN calls only) installed, therefore instead of re-investing on a new IP PBX, some offices install a VoIP gateway 160 along with the conventional PBX 150 for converting analog PSTN calls into VoIP calls and routing these calls to the Internet 30, as shown in FIG. 1(b).
For households that have only one or two telephone lines to the PSTN, the IP PBX or VoIP gateway is way too expensive. In addition, installing, using, and maintaining the IP PBX or VoIP gateway usually require experienced personnel, which is also not commonly available in a household. Besides, the installation of the IP PBX 100 or PBX 150 needs to break up the connection between the PSTN 10 and the existing wiring 20 and interpose the IP PBX 100 or PBX 150 therebetween, as shown in FIGS. 1(a) and 1(b). The existing wiring 20 is destructed or altered to accommodate the IP PBX 100 or PBX 150. Another shortcoming is that, even though a user could still make either PSTN calls or VoIP calls via the IP PBX 100 and the PBX 150, once the PBXs are not functioning for any reason, all voice communications to the outside world is disrupted. In addition, before the malfunctioned PBXs are fixed or replaced, an experienced technician is required to reconnect the PSTN 10 back to the existing wiring 20 so as to restore voice communications through the PSTN 10.
Therefore, there is a need for a simple infrastructure for households so that existing wiring remains intact, existing analog telephone sets could be used to make VoIP calls and PSTN calls as well, and, when the communications device such as the IP PBX is broken down, the voice communications to the PSTN could be restored easily without an experienced technician.